RU2676841C2 - Unidirectional catheter control handle with tensioning control - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: group of inventions relates to medical equipment, specifically, to electrode catheters used for stimulating and mapping electrical activity of the heart and ablation of areas with disturbed electrical activity, and, in particular, to catheters with a deflectable portion and a control handle to control deflection. Catheter includes a flexible tubing, and a control handle proximal of the flexible tubing. Control handle has a barrel housing and a piston in a telescopic configuration, and a tension adjustment assembly. Piston has a thumb control. Piston is configured for longitudinal movement relative to the housing by a user via the thumb control for deflecting the tubing. Tension adjustment assembly includes a force member adapted to apply a force on the piston, and a knob rotationally coupled to the force member. Knob is adapted for rotation by the user to adjust the force applied on the piston by the force member. Catheter also comprises a puller wire extending through the catheter and having a proximal end anchored in the control handle. And the puller wire is responsive to longitudinal movement of the piston relative to the barrel housing. Tension adjustment assembly further includes at least one rotational guide provided on the barrel housing, and wherein, the knob has at least one pin engaged with the guide, wherein the guide is configured to limit rotation of the handle. According to the second embodiment of the catheter, the tension adjustment assembly includes a set screw, adapted to apply a force on the piston, and a knob mounted on the barrel housing and having an axial bore receiving a portion of the set screw. Knob and the set screw are rotationally coupled to each other. Barrel housing has a radial bore extending between the knob and the barrel housing and receiving another portion of the set screw. Knob is adapted for rotation by the user to adjust the force applied by the set screw on the piston. Tension adjustment assembly further includes at least one rotational guide provided on the barrel housing. Knob has at least one pin engaged with the guide, wherein the guide is configured to limit rotation of the handle. Said at least one rotational guide is recessed to receive at least a distal portion of the at least one pin extending from the knob. According to the third embodiment, the catheter comprises an elongated catheter body, an intermediate deflectable section and a control handle proximal of the catheter body. Control handle has a barrel housing and a piston having a proximal portion substantially surrounded by a barrel housing, and the distal portion located outside the barrel housing; and a tension adjustment assembly. Distal portion of the piston has a thumb control. Piston is configured for longitudinal movement relative to the housing by a user via the thumb control for deflecting the intermediate section. According to the fourth embodiment of the catheter, the adjustment assembly includes a set screw, configured for a frictional engagement with the piston, and a knob mounted on the housing and rotatably coupled to the set screw. Knob is rotatable in one direction to increase the frictional engagement and rotatable in an opposition direction to decrease the frictional engagement. Wherein increasing the frictional engagement locks the piston and the housing in a desired position, and decreasing the frictional engagement unlocks the piston and the housing and allows repositioning of the piston and the housing relative to each other. Inventions have a tension adjustment assembly that allows the catheter to be detachably fixed at the desired deflection and allows the deflection of the catheter to be adjusted.EFFECT: unidirectional catheter control handle with tensioning control is proposed.18 cl, 7 dwg

Description

FIELD OF THE INVENTION

The present invention relates to catheters, in particular to catheters with a deflectable part and a control handle for controlling the deflection.

BACKGROUND OF THE INVENTION

Electrode catheters have been widely used in medical practice for many years. They are used to stimulate and map the electrical activity of the heart, as well as to ablate areas with impaired electrical activity. In practice, an electrode catheter is inserted into the main vein or artery, for example, into the femoral artery, and then sent to the corresponding chamber of the heart. In the heart, the ability to control the exact position and orientation of the tip of the catheter is very important and largely determines the benefits of using a catheter.

A typical mapping or ablation catheter has an elongated catheter body, an intermediate deflectable section, a distal section on which one or more electrodes are located, and a control handle in which the proximal end of the at least one pulling wire is fixed. A draw wire extends distally through the catheter body and at least through an intermediate deflectable section. The distal end of the draw wire is typically fixed at or near the junction of the deflected section and the distal section. Essentially, a compression winding is provided surrounding the draw wire in the catheter body, where the distal end of the compression winding determines the place where the desired deflection begins. Around the drawing wire located distally relative to the compression winding is essentially a protective tube that protects the outer tube of the catheter from being cut by the drawing wire during deflection.

Unidirectional catheters use a single draw wire. Control handles of a unidirectional catheter include control handles that use a piston contained in the handle body and configured to longitudinally move relative to it to actuate the pull wire and achieve the desired deflection. Since the patient’s heart is functioning, there is blood flow in it, and the walls and chambers move, forces act on the catheter, which in the absence of constant attention and manipulation by the operator can lead to a change or loss of catheter deflection. Thus, the piston may have a friction causing element, for example, an annular gasket located between the piston and the handle body, which maintains the desired deflection and prevents the piston from sliding or moving under the influence of these forces. However, the annular gasket may not provide constant friction sufficient to hold the piston and maintain the desired deflection.

Accordingly, it is desirable to create a control handle for a unidirectional catheter with a tension mechanism that can detachably lock the piston in a specific position and allows you to change the position of the piston and adjust the amount of force required to change the position of the piston. Moreover, it is desirable that the mechanism allows control of the tension of the deviation to provide the user with an improved ability to accurately position the catheter.

SUMMARY OF THE INVENTION

The present invention relates to a unidirectional catheter with an improved control handle having a tension control unit that allows the catheter to be detachably fixed at a desired deviation and allows the catheter resistance to be deflected.

In one embodiment, the catheter includes a flexible tube and a control handle that has a housing and a piston in a telescopic configuration, where the piston has a thumb control and the piston slides longitudinally relative to the body by a user with a thumb control to deflect the tube . An advantage is that the control handle includes a tension control unit in which there is a power element configured to apply force to the piston and a handle rotationally connected to the power element, the handle being rotatable by the user to adjust the force applied to piston by a power element. The force includes contact, pressure and / or friction between the piston and the housing of the control handle and allows the piston to be detachably fixed in the desired position relative to the housing, to change the position relative to the housing and to regulate the degree of freedom with which the piston can move relative to the housing. The tension control assembly may also include a guide that limits the range of motion of the handle so as to prevent damage to the piston and / or housing or the dismantling or disassembly of the tension control assembly.

In a more detailed embodiment, the power element includes a set screw passing through an axial hole formed in the handle, where the distal end of the set screw passes through a threaded hole formed in the housing, so that the distal end comes into adjustable contact with the piston for applying force. The distal end may have a non-slip surface for contact with the housing.

The handle is rotatable in one direction to increase the force exerted by the set screw on the piston, and in the opposite direction to reduce the force exerted by the set screw on the piston, where an increase in frictional engagement fixes the piston and the housing in the desired position, and a decrease in friction engagement unlocks from the piston and the housing, allowing you to change the position of the piston and the housing relative to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will be better understood by reference to the following detailed description, which should be considered in conjunction with the accompanying drawings.

1 is a perspective view of a catheter in accordance with an embodiment of the present invention.

FIG. 2 is a side cross-sectional view of the catheter shown in FIG. 1, including the connection between the catheter body and the intermediate deflectable section.

FIG. 2A is a rear sectional view of the intermediate deflectable section of FIG. 2 along line A-A.

FIG. 3 is a side cross-sectional view of the catheter shown in FIG. 1, including a connection between an intermediate deflectable section and a distal section.

Figure 3 presents a side view in cross section of the catheter shown in figure 1, including a point electrode.

Figure 4 presents a side view in section of the handle of the catheter shown in figure 1.

FIG. 5 is an exploded perspective view of the components of a tension control assembly according to an embodiment of the present invention, including a guide plate.

Figure 6 presents a side view in cross section of a node for regulating tension.

Figure 7 presents a perspective view with a spatial separation of the components of the handle control the tension of the node shown in Fig.5 and 6.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows an embodiment of a catheter 10 with an elongated catheter body 12 deflected by an intermediate section 14, a distal section 15 with a point electrode 17 and an improved control handle 16 that uses a piston 54 located in the handle body for unidirectional deflection, with the advantage being the fact that the catheter has a tension control mechanism 55, which allows the operator to detach the piston in a specific position relative to the handle body and allows changing The position of the piston as well as the amount of force required to change the position of the piston. Thus, the control handle provides the user with the improved ability to accurately position the catheter in the patient.

As shown in FIGS. 1 and 2, the catheter body 12 comprises an elongated tubular structure having one axial or central lumen 18. The catheter body 12 is flexible, i.e. bendable but substantially incompressible along its length. The catheter body 12 may be of any suitable design and may be made of any suitable material. The present preferred construction comprises an outer wall 20 made of polyurethane or PEBAX. The outer wall 20 comprises an integrated braided stainless steel mesh or the like. to increase the torsional rigidity of the catheter body 12, so that when the control handle 16 is rotated, the intermediate section 14 of the catheter 10 rotates accordingly.

The external diameter of the catheter body 12 is not critical, but preferably does not exceed about 8 French points, and more preferably 7 French points. Similarly, the thickness of the outer wall 20 is not critical, but it is thin enough so that the central lumen 18 can accommodate the pull wire, conductive conductors, and any other desired wires, cables or tubes. If desired, the inner surface of the outer wall 20 may be coated with a reinforcing tube 22 to provide improved torsion resistance. In the described embodiment, the catheter has an outer wall 20 with an outer diameter of from about 0.23 cm (0.090 inches) to about 2.39 cm (0.94 inches) and an inner diameter of from about 0.155 cm (0.061 inches) to about 0.165 mm ( 0.065 inch).

The distal ends of the reinforcing tube 22 and the outer wall 20 are fixedly attached near the distal end of the catheter body 12 by forming an adhesive joint 23 with polyurethane adhesive or the like. A second adhesive joint (not shown) is formed between the proximal ends of the reinforcing tube 20 and the outer wall 22 using a slower drying but stronger adhesive, such as polyurethane.

The components that pass between the control handle 16 and the deflectable section 14 pass through the central lumen 18 of the catheter body 12. These components include conductive wires 40 for the point electrode 17 and ring electrodes 21 located on the distal section 15, an irrigation tube 38 for delivery fluid to the point electrode, cable 74 for the electromagnetic position / placement sensor 34 located in the distal section 15, a draw wire 42 to deflect the intermediate section 14 and a pair of thermo wires ares 41, 43 for measuring the temperature at the distal section 15.

Figures 2 and 2A illustrate an embodiment of an intermediate section 14, which comprises a short section of a tube 19. The tube also has a braided mesh construction, but with many off-axis gaps, for example, gaps 26, 27 and 28. The first lumen 26 comprises a draw wire 42 for unidirectional deflection of the intermediate section. The second lumen 27 contains conductive conductors 40, the thermocouple wires 41 and 43 and the sensor cable 74. The third lumen 28 contains an irrigation tube 38.

The tube 19 of the intermediate section 14 is made of a suitable non-toxic material that is more flexible than the catheter body 12. A suitable material for the tube 19 is braided polyurethane, i.e. polyurethane with integrated braided stainless steel mesh or the like The size of each lumen is not critical, but it is sufficient to accommodate the corresponding components passing through it.

Means for attaching the catheter body 12 to the intermediate section 14 are illustrated in FIGS. 2 and 2A. The proximal end of the intermediate section 14 contains an outer circular slot 25 that receives the inner surface of the outer wall 20 of the catheter body 12. The intermediate section 14 and the catheter body 12 are bonded with glue or the like.

If desired, a separator (not shown) can be placed between the distal end of the reinforcing tube (if present) and the proximal end of the intermediate section in the catheter body. The separator provides a flexible transition at the junction of the catheter body and the intermediate section, which allows this connection to smoothly bend without creasing or twisting. A catheter having such a separator is described in US Pat. No. 5,964,757, the contents of which are incorporated herein by reference.

The draw wire 42 is preferably coated with Teflon.RTM. The drawing wire can be made of any suitable metal, such as stainless steel or nitinol, and the Teflon coating gives the drawing wire lubricity. Preferably, the diameter of the drawing wire ranges from about 0.0152 cm to about 0.0254 cm (0.006 to about 0.010 inches).

A portion of the draw wire in the catheter body 12 passes through a compression coil 35 that surrounds the wire. The compression coil 35 extends from the proximal end of the catheter body 12 to the proximal end of the intermediate section 14 or adjacent to it. The compression winding can be made of any suitable metal, preferably stainless steel, and must be tightly wound to provide flexibility, i.e. ability to bend, but at the same time possess compressive strength. The inner diameter of the compression winding is preferably slightly larger than the diameter of the draw wire. In the catheter body 12, the outer surface of the compression winding 35 is also covered with a flexible non-conductive sheath 39, for example, made of a polyimide tube. A portion of the draw wire located distally relative to the compression winding 35 may pass through a protective plastic sheath 37, for example of TEFLON.RTM., To prevent the draw wire from cutting into the tube 19 of the intermediate section 14 during deflection.

The proximal end of the draw wire 42 is fixed in the control handle 16, as further described below. The distal end of the drawing wire is fixed in the distal section 15, for example, using a T-shaped rod 44, as shown in Fig.3.

As shown in FIGS. 3 and 3A, the distal section 15 includes a tube 24 extending between the deflectable intermediate section 14 and the point electrode 17. The tube 24 has a central lumen 48 in which the sensor 34 is located and which allows components, including the conductive conductors of the point and ring electrodes 40T and 40R, a pair of thermocouple wires 41 and 43, an irrigation tube 38, and a sensor cable 74 extending to the point electrode 17 to change their orientation. At least one ring electrode 21 is mounted on the tube 24.

The point electrode 17 is received at the distal end of the tube 24. On the proximal surface of the point electrode, through holes 60 and 62 are formed to receive the distal ends of the conductive point electrode 40T and the thermocouple wires 41 and 43, respectively. An axial channel 66 is formed in the point electrode 17, which receives the distal end of the irrigation tube 38. The axial channel 66 connects the transverse branches 68 and the fluid openings 69 through which the liquid passes from the irrigation tube to the outside of the point electrode.

As shown in FIG. 4, the longitudinal movement of the draw wire 42 relative to the catheter body 12, which leads to the deviation of the end section 12, is performed by suitable manipulations with the control handle 16. The distal end of the control handle 16 contains a piston 54 made with the possibility of telescopic movement relative to the body control handles or cylinder 80. The outer surface 82 of the piston substantially surrounds and is in sliding contact with it the inner surface 84 of the cylinder 80. Proximal to Heff, the catheter body 12 is connected to the piston 54 by means of a shrink sleeve 31.

The piston 54 has a thumb control 56 located distally and outside of the housing 80 and allowing the user to grab the cylinder 80 and move it distally or proximal, for example, with the thumb, relative to the housing, manipulating the drawing wire 42. The surfaces 82 and 84 slide relative to each other each other as the piston moves longitudinally relative to the cylinder 80 by the user using the thumb control 56. An annular gasket 86 mounted on the piston and located between the By surfaces 82 and 84, it provides friction that provides better control and “feel” during the movement of the piston 54 relative to the cylinder 80. However, in accordance with an aspect of the present invention, the control handle includes a tension control unit 90, which allows the user to detach the piston in place , reposition the piston and adjust the amount of friction between the piston and the cylinder 80 to control the amount of force required to move the piston 54.

As shown in FIGS. 5 and 6, the tension control unit 90 includes a power or contact element 92 configured to contact the piston 54, and an adjustable micro-tension control knob 94 configured to adjust the amount of contact, pressure and / or friction ( these terms are used interchangeably herein) provided by the contact element to the piston. In the illustrated embodiment, the handle has a circular cross section, and the element 92 includes a set screw 96 with a non-slip and friction-promoting end 98, for example, of plastic with low durometric hardness, which is received in the central axial hole 100 of the handle 94. The screw 96 and the handle 94 are rotationally connected to each other, for example, by means of connecting pins 102 (FIG. 7), which contact and fixedly engage the screw housing 96 through threaded radial holes 106 formed in the handle 94. The screw and the handle The cup can also be rotationally joined using glue or sonic welding. The distal end 98 of the screw is received in a threaded hole 108 formed in the raised surface portion 115 of the cylinder 80.

Essentially around the opening 108 there is at least one guiding rotational movement track 110. In the illustrated embodiment, there are a pair of diametrically opposed recessed semicircular tracks. Along the guides 110, diametrically opposite protrusions or pins 112 slide from the inner adjacent surface of the handle 94. The guides can be formed on a raised portion 115 of the cylinder 80 (FIG. 6). Alternatively, the assembly 90 may include a circular guide plate 117 (FIG. 5) with guides 110 formed thereon and a central threaded hole 109 centered with the hole 108. The guide plate is attached to the outer surface 82 of the cylinder 80 and is located between the cylinder 80 and the handle 94 .

In practice, the user manipulates the thumb control 56, moving it distally or proximal to the cylinder 80, and reaches the desired catheter deflection. To fix, release and / or provide a more intense “sensation” or greater tension when moving and adjusting the control element with thumb 56 and piston 54, the user can change the tension by turning the knob 94. When the knob 94 is rotated, the set screw 96 rotationally connected thereto or moves inward or extends from the hole 108 in the cylinder, applying more or less contact, pressure and / or friction forces with its distal end 98 to the outer surface of the cylinder 80. When the handle 94 is loosened, increasing the piston 54 moves relative to the cylinder 80. When the handle 94 is tightened, the piston 54 moves less relative to the cylinder. The maximum and minimum levels of effort are mainly limited by the ends 114 of the guides 100, which do not allow the pins 112 and, therefore, the handle 94 to rotate in either clockwise or counterclockwise directions to the set positions, which can damage the piston or disassemble the assembly 90. In the illustrated In an embodiment, each guide 110 has a stroke of approximately 160 degrees. Upon reaching the maximum tension limited by the rails 110, the piston locks in place to maintain the desired deflection. Upon reaching the maximum attenuation limited by the guides 110, the piston can be easily moved and the set screw 96 or handle 94 is completely detached from the cylinder 80. The outer peripheral surface 116 of the handle can be ribbed or otherwise textured so as to provide a more tangible surface for the user.

In the illustrated embodiment, the tension control assembly 90 is located closer to the distal end of the cylinder 80. However, it should be understood that the assembly 90 can be located anywhere on the cylinder 80, while the contact element 92 or the set screw 96 can come into contact with the outer surface 82 of the cylinder and get out of it.

As shown in FIG. 4, the draw wire 42, the conductive wires 40 of the point electrode 17, and any ring electrodes, as well as the cable of the electromagnetic sensor 74 pass through the piston 54. The pull wire 42 is fixed to a fixing pin 57 located proximally relative to the piston 54. Conducting conductors 40 and the cable of the electromagnetic sensor 74 pass through the first tunnel 58 located at the side of the control handle 16. The cable of the electromagnetic sensor 74 is connected to the PCB 64 for proxim at the far end of the control handle. Wires 73 connect the circuit board 64 to a computer and a monitor for outputting images (not shown).

In the piston 54, the cable of the electromagnetic sensor 74 and the conductors 40 are located in the carrier tube 77a, and the pull wire 42 is located in another carrier tube 77b so that the wires and cables in the vicinity of the adhesive joint 53 can move longitudinally.

The conductive conductors 40 pass through the lumen 28 (FIGS. 2 and 2A) of the tube 19 of the deflectable intermediate section 14 and the central lumen 18 of the catheter body 12. A part of the conductive conductors passing through the central lumen 18 of the catheter body 12 and the proximal end of the lumen 27 can be enclosed a protective sheath (not shown), which may be made of any suitable material, preferably polyimide. The protective sheath from its distal end is fixed to the proximal end of the intermediate section 14 by gluing it in the lumen 27 using polyurethane adhesive or the like. Each conductive electrode conductor has a proximal end, which ends with a connector on the proximal end of the control handle 16.

The foregoing description is set forth with reference to specific examples of embodiments of the present invention. Specialists in the field of engineering and technology to which the present invention relates will understand that the described construction allows modifications and changes that do not significantly violate the principles and essence of the present invention and do not go beyond its scope. It should be understood that the drawings are not necessarily represented to scale. Thus, the foregoing description should not be construed as referring only to the specific structures described and presented in the accompanying drawings. The preceding description is more likely to be consistent and support the following claims, reflecting the full and satisfactory scope of the present invention.

Claims (60)

1. A catheter containing: flexible tube; and a control handle located proximally relative to the flexible tube, the control handle having: a cylindrical body and a piston in a telescopic configuration, wherein the piston has a thumb control and the piston is longitudinally movable relative to the body by a user with a thumb control to deflect the tube; and tension control unit, including: a power element configured to apply force to the piston; a handle rotationally connected to the power element, the handle being rotatable by the user to control the force applied to the piston by the power element; however, the catheter further comprises a pulling wire passing through the catheter and having a proximal end fixed in the control handle, and the pulling wire responds to the longitudinal movement of the piston relative to the cylindrical body; moreover, the tension control unit further includes at least one rotation guide provided on the cylindrical body, and wherein the handle has at least one pin engaging the guide, the guide being configured to limit the rotation of the handle. 2. The catheter according to claim 1, in which the power element includes a set screw. 3. The catheter according to claim 2, in which the set screw passes through an axial hole formed in the handle. 4. The catheter according to claim 2, in which the distal end of the set screw passes through a threaded hole formed in a cylindrical body, and the distal end is in adjustable contact with the piston. 5. The catheter according to claim 2, in which the set screw has a non-slip distal end for contact with a cylindrical body. 6. The catheter according to claim 1, wherein said at least one rotation guide is recessed to receive at least the distal portion of said at least one pin extending from the handle. 7. The catheter according to claim 1, wherein said at least one rotation guide has a substantially semicircular shape. 8. The catheter according to claim 1, in which the cylindrical body has a hole that receives the distal part of the power element, and the specified at least one guide rail partially passes around the hole. 9. A catheter containing: flexible tube; a control handle located proximally relative to the flexible tube, the control handle having: a cylindrical body and a piston in a telescopic structure with a cylindrical body, the piston part having a thumb control, the piston being longitudinally movable relative to the body by the user using the thumb control to deflect the tube; and tension control unit, including: a set screw configured to apply force to the piston; a handle mounted on a cylindrical body and having an axial hole that receives a part of the set screw, the handle and set screw being rotationally connected to each other, moreover, the cylindrical body has a radial hole extending between the handle and the cylindrical body, and the radial hole takes another part of the set screw, and moreover, the handle is made to rotate by the user to control the force applied by the set screw to the piston; however, the catheter further comprises a pulling wire passing through the catheter and having a proximal end fixed in the control handle, and the pulling wire responds to the longitudinal movement of the piston relative to the cylindrical body; wherein the tension control unit further includes at least one rotation guide provided on the cylindrical body, and wherein the handle has at least one pin engaging the guide, the guide being configured to limit the rotation of the handle; wherein said at least one rotation guide is recessed to receive at least a distal portion of said at least one pin extending from the handle. 10. The catheter according to claim 9, in which the specified effort includes at least one that is selected from the group consisting of contact, pressure and friction. 11. The catheter according to claim 9, in which the distal end of the set screw is made with the possibility of adjustable contact with a cylindrical body. 12. The catheter according to claim 9, in which the handle and the set screw are rotationally connected using at least one pin. 13. The catheter according to claim 9, in which the handle is made to rotate in one direction to increase the force exerted by the set screw on the piston, and in the opposite direction to reduce the force exerted by the set screw on the piston. 14. The catheter according to claim 9, further comprising a drawing wire extending through the flexible tube, the drawing wire having a proximal end fixed in the control handle. 15. The catheter according to claim 9, in which the tension control unit further includes at least one rotation guide restricting the rotation of the handle. 16. The catheter of claim 15, wherein the handle has at least one pin engaged with said at least one rotation guide. 17. A catheter containing: elongated catheter body; intermediate deflectable section; a control handle located proximally relative to the catheter body, the control handle having: a cylindrical body and a piston having a proximal part essentially surrounded by a cylindrical body, and a distal part located outside the cylindrical body, the distal part having a thumb control, the piston being made to be longitudinally movable by the user relative to the body using the thumb control to reject the intermediate section; and tension control unit, including: a set screw configured to apply force to the piston, the set screw having a head part and a main part; a handle mounted on a cylindrical body and having an axial hole that receives the head of the set screw, the handle and set screw being rotationally connected to each other, moreover, the cylindrical body has a radial hole extending between the handle and the cylindrical body, and the radial hole receives the main part of the set screw, and moreover, the handle is made to rotate by the user to control the force applied by the set screw to the piston; however, the catheter further comprises a pulling wire passing through the catheter and having a proximal end fixed in the control handle, and the pulling wire responds to the longitudinal movement of the piston relative to the cylindrical body; wherein the tension control unit further includes at least one rotation guide provided on the cylindrical body, and wherein the handle has at least one pin engaging the guide, the guide being configured to limit the rotation of the handle; wherein said at least one rotation guide is recessed to receive at least a distal portion of said at least one pin extending from the handle. 18. A catheter containing: elongated catheter body; intermediate deflectable section; and a control handle located proximally relative to the catheter body, the control handle having: a housing and a piston, wherein the piston has a thumb control, and the housing and piston are longitudinally movable relative to each other by the user using the thumb control to reject the intermediate section; control unit, including: a set screw made with the possibility of frictional engagement with the piston; and a handle mounted on the housing and rotationally connected to the set screw, the handle being rotatable in one direction to increase friction engagement, and rotatably in the opposite direction to reduce friction engagement, moreover, an increase in friction engagement fixes the piston and the housing in the desired position, and a decrease in friction engagement removes the lock from the piston and the housing, allowing the piston and the housing to change relative to each other; however, the catheter further comprises a pulling wire passing through the catheter and having a proximal end fixed in the control handle, and the pulling wire responds to the longitudinal movement of the piston relative to the housing; wherein the tension control unit further includes at least one rotation guide provided on the cylindrical body, and wherein the handle has at least one pin engaging the guide, the guide being configured to limit the rotation of the handle; wherein said at least one rotation guide is recessed to receive at least a distal portion of said at least one pin extending from the handle.

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